Problem #1.7

Find the time ratio of a crank-rocker linkage that has a 100-mm frame, a 25-mm crank, a 90-mm coupler, and a 75-mm rocker.Figure 1. Crank-Rocker Linkage.

Assuming that the driver motor operates at a constant speed, it is easy to find the time ratio. As shown in figure 1., the first thing is to determine the two crank positions, which mark the beginning and end of the working stroke or rocking motion. The angle between can be determine and the time ratio is determine using the following formula

Q=time of advance stroke/time of return stroke

To see a working model diagram click here Crank-Rocker Linkage.